Shrews’ Heads Shrink and Grow With the Seasons

Creating shrunken heads—small, severed human heads that are widely associated with Voodoo and tribal rituals—is a gruesome process, apparently much more than what’s shown in Beetlejuice. But leave it to the animal kingdom to prove there’s a natural, less sinister way to shrink a head.

Red-toothed shrews’ heads seasonally reverse sizes once they’re adults, something called the Dehnel phenomenon, which was first discovered in 1949. We now have more information on how much a shrew’s skull ac